Devices of this type are used in certain assemblies, e.g. at refineries in the paper industry. The assembly is easy to accomplish in those cases where the axial load acts in one direction only. One of the bearings is assembled radially and guided with the outer race ring mounted with a slight interference fit in the bearing housing. The outer race ring of the other bearing is fitted with radial clearance and is preferably assembled with a small axial clearance. The outer race ring of the outer bearing rests at the same time against a number of packets of springs, which together provide an overall axial load of sufficient size. At high speeds, the overrall spring force is designed to be great enough to compensate for occurring counter-acting axial loads in the bearing packet due to centrifugal forces and gyroscopic forces from the rolling bodies of the bearings and axial loads on the bearing, caused by radial forces on the radially guiding bearing. Hereby is ascertained that the outer race ring of the bearing with radial clearance always rests against the packet of springs with a substantially unaltered axial clearance in relation to its bearing seat. The packet of springs may possibly be supplemented with or be replaced by hydraulically generated forces.
By means of an arrangement described above, a clearance-free bearing assembly is obtained and an outer race ring for the bearing with radial clearance, which is not engaging its axial bearing seat. Radial motions of the shaft due to shape deviations of the races or shaft seats of the bearings, which cause radial warpings, are not absorbed as radial rubbing movement of the outer race ring of the bearing with radial clearance but result in a harmless axial wobbling motion of the last mentioned outer race ring against the packet of springs.
If the outer race ring of the bearing with radial clearance should be pressed against the bottom of its axial bearing seat, there would occur a radial rubbing resulting in abrasion corrosion. The bearing assembly furthermore should get a slackness, which may result in a large increase of the abrasion corrosion if rotational radial loads occur.
In those cases where the thrust load changes direction, the assembly will be more difficult to accomplish, particularly if a clearance-free support is required due to high speed or for other reasons. The outer race rings of both bearings in such cases must be spring loaded and furthermore have a loose fit. Radial warpings caused by shape deviations cannot be avoided and of the reasons mentioned above, the risk for abrasion corrosion at high rotational speed, is high at the outer race ring, which contacts its axial bearing seat, as radial rubbing motions cannot be prevented by a loose radial fit or by an outer race ring with radial clearance.